SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '764dcadc1b4d87e3ca6d094df5833a690a3d9c542e483fef4b667c865c9c7527' 
  AND token = 'QatWnFX2HOvREtNiwFVW7OuD1qpfbK2jMcvEuJu24vA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}